A novel nucleoside from the edible mushroom, Tricholoma japonicum.

A novel nucleoside, 9-β-D-ribopyranosylpurine (2), along with three known nucleosides, adenosine (1), uridine (3) and nebularine (4), were isolated from the edible mushroom, Tricholoma japonicum. The structure of 2 was determined as 9-β-D-ribopyranosylpurine by comparing the reported spectral data of 2 with that of a synthetic compound. Isolation of the glycoside, which contains the sugar ribopyranose, from natural resources is very unusual. There are reports on the synthesis of 9-β-D-ribopyranosylpurine (2), but this is the first report on the isolation from natural resources. The antiproliferative activity of compounds 1-4 was evaluated using human umbilical vein endothelial cells. Compound 4 showed the highest inhibitory activity.